Feeding device for rock drills



Feb. `9, 1932. w. A. SMITH, SR 1,844,873

FEEDING DEVICE FOR ROCK DRILLS Filed Jan. 4. 1929 IN V EN TOR.

Patented Feb. 9, 1932 UNITED STATES PATENT OFFICE WILLIAM A. SMITH, SR., OF EASTON, PENNSYLVANIA, ASSIGNOR T INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION 0F NEW JERSEY FEEDING DEVICE FOR ROCK DRILLS Application :tiled January 4, 1929. Serial No. 330,260.

This invention relates to rock drills, but more particularly to a feeding device for fluid actuated rock drills of the hammer type.

One object of the invention is to actuate the rock drill relatively to its support, such as a shell, to insure the correct position of the percussive element with respect to the working implement so that the entire drilling mechanism may advance in accordance with the progress of the drill steel into the work.

Another object is to obtain a compact device which may be cheaply constructed and is inexpensive to maintain, and still another object is to so connect the rock drill to the feeding piston in such manner that the rate of movement of the rock drill will be a multiple of the rate of movement of the feeding piston.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings illustrating a practical embodiment of the invention and in which similar reference characters refer to similar parts,

Figure 1 is a longitudinal elevation, partly in section, of a rock drill and a shell therefor equipped with a feeding device constructed inaccordance with the practice of the invention Figure 2 is a transverse view through Figure 1 on the line 2-2 looking in the direction indicated by the arrows, and

Figure 3 is a longitudinal View in perspective and partly in section of a detail.

Referring more particularly to the drawings, A represents a rock drill and B a shell which serves as a support for the rock drill and has a cone C for engagement with suitable clamping means (not shown) whereby the shell may be secured to a support, such as a quarry bar or drill column.

The rock drill illustrated is of the drifter type and comprises a cylinder D and front and back heads E and F respectively.

In accordance with the usual practice the cylinder D is provided with lateral guides G which extend into guideways H in the inner surface of the sides J of the shell B. The guideways H extend throughout the length of the shell B so that the guides G of the cylinder D may, if circumstances require, overrun the ends of the shell B.

In accordance with the present invention, means are provided for actuating the rock drill A longitudinally of the shell B to advance the rock drill towards the work and to retract it therefrom. The means provided for this purpose comprises a feeding cylinder K which, in order to form a compact structure, is disposed in the rearward end of the shell B. The feeding cylinder K is provided at its rearward end with a head L having an extension O which is threaded into the rearward end of' the cylinder K. A flange l on the head L seats on the rearward end of the shell B to which the head is secured by means of a bolt or bolts Q which extend through the flange P and may be threaded into the shell B, or votherwise suitably secured thereto.

W'ithin the cylinder K is a piston R provided in this instance with a removable rod S which extends through a head T in the front end of the cylinder lx and terminates at its projecting end in a fork U. The head T is preferably also threaded into the end of the cylinder K and in this instance has a reduced outward threaded extension V to receive a threaded cap lV which also serves to guide the rod S and bears against a collar X in the extension V for compressing apacking Y to seal the front end of the cylinder K.

'lhe rearward end Z of the rod S which extends through the piston R lis of somewhat smaller diameter than the main body portion of the rod and projects beyond the rearward end of the piston R. 1n the present in- A stance the projecting portion of the end Z is threaded to receive a cap which serves to secure the piston 1l firmly to the rod S.

The admission of pressure fluid into the ends of the cylinder K is controlled by a throttle valve c disposed in a. valve chamber d in the head L. The throttle valve c is of the rotary type and accordingly has al lever c whereb)v it may be rotated from one position to the other. The throttle valve. chas a central chamber f which may be in constant communication with a. source of pressure fiuid supply through a conduit (not shown) and a port g in the throttle valve o aiiords communication between the chamber f and supply passages L and j in the head L and leading from the valve chamber d. The supply passage h in this instance opens into the rearward end of the cylinder K and the supply passage j extends to a recess c in the head L.

In the periphery of the throttle valve 0 is a partly annular groove 0 which is of such extent that it may register with either or both of the supply passages h and j and an exhaust port p leading from the valve chamber d to the atmosphere.

Pressure fluid admitted into the recess c through the supply passage j may flow into a passage g in the rod S thi-ou h a tube r which extends through the rod to a point near the front end of the cylinder K, and a port R affords communication between the Iissa. e g and the front end of the cylinder n the rearward end of the tube 1' is a flange s which seats against the bottom of the recess and serves as a seat for a plug t which forms a closure for the recess and holds the tube 1' securely against endwise movement.

The projecting end or fork U of the rod S serves as a bearing for a shaft u on which may be journalled av multi-groove sheave or, if desired, a pair of single sheaves fv. The fork U is of such proportions that the outer surfaces w ma slidably engage guiding surfaces :v Iin the interior of the shell B for preventing lateral movement of the free end of the rod S and therefore also of the sheaves o.

In the construction shown a pair of flexible elements illustrated as cables y and a are trained over one slieave v. The cable y extends with its ends in a forwardly direction and has one end secured to a plate 2 at the front end of the shell B. The o posite end of the cable y which also exten s in a forwardly direction has secured thereto a bolt 3 which extends through a lug 4 on the front head E of the rock drill. A nut 5 is threaded on the bolt 3 for varying the tension of the cables y and z.

The cable a is trained over the other sheave o and extends with its ends in a rearwardly direction. One end 6 may be secured to a convenient point on the rock drill A, as for instance, to a lug 7 of the cylinder D, and the other end 8 of the cable z which also extends in a rearwardly direction may be secured to the shell B at a point rearwardly of the reai'wardmost limit of travel of the sheave fv.

The operation of the device is as follows: With the rock drill A in the position illustrated, which may be substantially the rearwardmost limiting position, and it be desired to actuate the rock drill in tlfe directie' of the work, the tlirotti valve. c i f to the position lili ed in g registers with the supply passa-ge h. Pressure fluid will then flow into the rearward end of the cylinder K and will act against the rearward surface of the piston R to exert a pressure thereon for driving/"the rock drill A forwardly in accordance with the degree of penetration of the working implement into the material being drilled.

With the throttle valve c in this position the forward end of the cylinder K will be open to the atmosphere through the port R, the passage g,'the tube 1, the recess lc, the supply passage j, the groove o and the exhaust port p. As drilling progresses the rock drill will gradually be advanced towards the work. In view of the means by which the rock drill A is connected to the piston R such as tlie sheave c and the cables y and a or their equivalents, the speed and distance of travel of the rock drill A will be double that of the piston R. This is advantageous since it permits the use of a relatively short feeding device which may be readily disposed within the shell B and thus avoid the protrusion of any considerable portion thereof from the shell and a drilling mechanism of standard type may therefore be readily equipped with a feeding device such as that disclosed without materially adding to the length of the unit. a

After the rock drill A has been advanced to its forwardmost limiting position the throttle valve c may be rotated so that the port g will register with the supply passage j. In this position the groove o will establish communica-tion between the supply passage h and the-exhaust port p so that the pressure fluid previously used for advancing the rock drill will then be exhausted to the atmosphere through these channels. In the new position of the throttle valve pressure fluid will How through the supply passage j into the recess k, thence through the tube r into the passage g in the rod S and from thence through the ort R into the. front end of the cylinder K ihr driving the iston and thus also the rock drill A rearwar y to the initial position.

I claim:

1. In a feedingdevice for rock drills, the combination of a rock drill and a shell, a feeding cylinder disposed within the shell and secured thereto, a piston in the cylinder having a rod, sheave means carried by the rod, and a pair of cables trained over the sheave means for transmitting movementof the pistons to the rock drill, one of said cables extending in a forwardly direction with both ends and havino' one end secured to the rock drill and the other end to the shell, and the other cable extending rearwardly with both ends and having one end secured to the rock drill and the other end secured to the shell.

2. In a feeding device for rock drills, the combination of a rock di l f d a. shell, a

the

and secured thereto, a piston in the cylinder having a rod, sheave means carried by the rod, a pair of cables trained over the sheave means for transmitting movement of the pistons to the rock drill, one of said cables extending in a forwardly direction with both ends and having one end secured to the rock drill and the other end to the shell the other cable extending rearwardly with both ends and having one end secured to the rock drill and the other end secured to the shell, and 31 bolt on the end of one cable to secure said cable to the rock drill and to vary the tension of the cables on the sheave means.

3. In a feeding device for rock drills, the combination of a rock drill and a shell, rotary means in the shell, a pair of flexible elements trained over the rotary means and about a common axis, each element having one end attached to an end of the rock drill and the other end attached to a corresponding end of the shell, and means for actuating the r0- tary means longitudinally of the shell.

4. In a feeding device for rock drills, the combination of a rock drill and a shell, rotary means in the shell, a flexible element trained over the rear side of the rotary means and having one end attached to the front end of the rock drill and the other end secured to the front end of the shell, a second flexible clement trained over the front side of the same rotary means and having one end attached to the rear end of the rock drill and the other end attached to the rear end of the shell, and means for actuating the rotary means longitudinally of the shell.

In testimony whereof I have signed this speciication.

WILLIAM A. SMITH, SR. 

